diff --git a/AGENTS.md b/AGENTS.md
index e6c5b1a5e92..daaa0b1ebd5 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -111,6 +111,7 @@
 - Agents MUST NOT modify baseline, inventory, ignore, snapshot, or expected-failure files to silence failing checks without explicit approval in this chat.
 - For targeted/local debugging, keep using the wrapper: `pnpm test -- <path-or-filter> [vitest args...]` (for example `pnpm test -- src/commands/onboard-search.test.ts -t "shows registered plugin providers"`); do not default to raw `pnpm vitest run ...` because it bypasses wrapper config/profile/pool routing.
 - Do not set test workers above 16; tried already.
+- Do not switch CI `pnpm test` lanes back to Vitest `vmForks` by default without fresh green evidence on current `main`; keep CI on `forks` unless explicitly re-validated.
 - If local Vitest runs cause memory pressure (common on non-Mac-Studio hosts), use `OPENCLAW_TEST_PROFILE=low OPENCLAW_TEST_SERIAL_GATEWAY=1 pnpm test` for land/gate runs.
 - Live tests (real keys): `CLAWDBOT_LIVE_TEST=1 pnpm test:live` (OpenClaw-only) or `LIVE=1 pnpm test:live` (includes provider live tests). Docker: `pnpm test:docker:live-models`, `pnpm test:docker:live-gateway`. Onboarding Docker E2E: `pnpm test:docker:onboard`.
 - Full kit + what’s covered: `docs/help/testing.md`.
diff --git a/docs/reference/test.md b/docs/reference/test.md
index e337e963e1d..08ebb2af3fc 100644
--- a/docs/reference/test.md
+++ b/docs/reference/test.md
@@ -11,8 +11,9 @@ title: "Tests"
 
 - `pnpm test:force`: Kills any lingering gateway process holding the default control port, then runs the full Vitest suite with an isolated gateway port so server tests don’t collide with a running instance. Use this when a prior gateway run left port 18789 occupied.
 - `pnpm test:coverage`: Runs the unit suite with V8 coverage (via `vitest.unit.config.ts`). Global thresholds are 70% lines/branches/functions/statements. Coverage excludes integration-heavy entrypoints (CLI wiring, gateway/telegram bridges, webchat static server) to keep the target focused on unit-testable logic.
-- `pnpm test` on Node 22, 23, and 24 uses Vitest `vmForks` by default for faster startup. Node 25+ falls back to `forks` until re-validated. You can force behavior with `OPENCLAW_TEST_VM_FORKS=0|1`.
+- `pnpm test` on Node 22, 23, and 24 uses Vitest `vmForks` by default for local runs with enough memory. CI stays on `forks` unless explicitly overridden. Node 25+ falls back to `forks` until re-validated. You can force behavior with `OPENCLAW_TEST_VM_FORKS=0|1`.
 - `pnpm test`: runs the full wrapper. It keeps only a small behavioral override manifest in git, then uses a checked-in timing snapshot to peel the heaviest measured unit files into dedicated lanes.
+- Files marked `singletonIsolated` no longer spawn one fresh Vitest process each by default. The wrapper batches them into dedicated `forks` lanes with `maxWorkers=1`, which preserves isolation from `unit-fast` while cutting process startup overhead. Tune lane count with `OPENCLAW_TEST_SINGLETON_ISOLATED_LANES=<n>`.
 - `pnpm test:channels`: runs channel-heavy suites.
 - `pnpm test:extensions`: runs extension/plugin suites.
 - `pnpm test:perf:update-timings`: refreshes the checked-in slow-file timing snapshot used by `scripts/test-parallel.mjs`.
diff --git a/scripts/test-parallel.mjs b/scripts/test-parallel.mjs
index 011211a307b..2901daad6b5 100644
--- a/scripts/test-parallel.mjs
+++ b/scripts/test-parallel.mjs
@@ -15,6 +15,7 @@ import {
   resolveTestRunExitCode,
 } from "./test-parallel-utils.mjs";
 import {
+  dedupeFilesPreserveOrder,
   loadUnitMemoryHotspotManifest,
   loadTestRunnerBehavior,
   loadUnitTimingManifest,
@@ -81,18 +82,17 @@ const testProfile =
     ? rawTestProfile
     : "normal";
 const isMacMiniProfile = testProfile === "macmini";
-// vmForks is a big win for transform/import heavy suites. Node 24 is stable again
-// for the default unit-fast lane after moving the known flaky files to fork-only
-// isolation, but Node 25+ still falls back to process forks until re-validated.
-// Keep it opt-out via OPENCLAW_TEST_VM_FORKS=0, and let users force-enable with =1.
+// vmForks is still useful for local transform-heavy runs, but do not flip CI
+// back to vmForks by default unless you have fresh green evidence on current
+// main. The retained Vite/Vitest module graph is the OOM pattern we keep
+// tripping over under CI-style pressure. Keep it opt-out via
+// OPENCLAW_TEST_VM_FORKS=0, and let users force-enable with =1 for comparison.
 const supportsVmForks = Number.isFinite(nodeMajor) ? nodeMajor <= 24 : true;
+const preferVmForksByDefault =
+  !isCI && !isWindows && supportsVmForks && !lowMemLocalHost && testProfile !== "low";
 const useVmForks =
   process.env.OPENCLAW_TEST_VM_FORKS === "1" ||
-  (process.env.OPENCLAW_TEST_VM_FORKS !== "0" &&
-    !isWindows &&
-    supportsVmForks &&
-    !lowMemLocalHost &&
-    (isCI || testProfile !== "low"));
+  (process.env.OPENCLAW_TEST_VM_FORKS !== "0" && preferVmForksByDefault);
 const disableIsolation = process.env.OPENCLAW_TEST_NO_ISOLATE === "1";
 const includeGatewaySuite = process.env.OPENCLAW_TEST_INCLUDE_GATEWAY === "1";
 const includeExtensionsSuite = process.env.OPENCLAW_TEST_INCLUDE_EXTENSIONS === "1";
@@ -345,15 +345,46 @@ const { memoryHeavyFiles: memoryHeavyUnitFiles, timedHeavyFiles: timedHeavyUnitF
         memoryHeavyFiles: [],
         timedHeavyFiles: [],
       };
+const unitSingletonBatchFiles = dedupeFilesPreserveOrder(
+  unitSingletonIsolatedFiles,
+  new Set(unitBehaviorIsolatedFiles),
+);
+const unitMemorySingletonFiles = dedupeFilesPreserveOrder(
+  memoryHeavyUnitFiles,
+  new Set([...unitBehaviorOverrideSet, ...unitSingletonBatchFiles]),
+);
 const unitSchedulingOverrideSet = new Set([...unitBehaviorOverrideSet, ...memoryHeavyUnitFiles]);
 const unitFastExcludedFiles = [
   ...new Set([...unitSchedulingOverrideSet, ...timedHeavyUnitFiles, ...channelSingletonFiles]),
 ];
-const unitAutoSingletonFiles = [
-  ...new Set([...unitSingletonIsolatedFiles, ...memoryHeavyUnitFiles]),
-];
+const defaultSingletonBatchLaneCount =
+  testProfile === "serial"
+    ? 0
+    : unitSingletonBatchFiles.length === 0
+      ? 0
+      : isCI
+        ? Math.ceil(unitSingletonBatchFiles.length / 6)
+        : highMemLocalHost
+          ? Math.ceil(unitSingletonBatchFiles.length / 8)
+          : lowMemLocalHost
+            ? Math.ceil(unitSingletonBatchFiles.length / 12)
+            : Math.ceil(unitSingletonBatchFiles.length / 10);
+const singletonBatchLaneCount =
+  unitSingletonBatchFiles.length === 0
+    ? 0
+    : Math.min(
+        unitSingletonBatchFiles.length,
+        Math.max(
+          1,
+          parseEnvNumber("OPENCLAW_TEST_SINGLETON_ISOLATED_LANES", defaultSingletonBatchLaneCount),
+        ),
+      );
 const estimateUnitDurationMs = (file) =>
   unitTimingManifest.files[file]?.durationMs ?? unitTimingManifest.defaultDurationMs;
+const unitSingletonBuckets =
+  singletonBatchLaneCount > 0
+    ? packFilesByDuration(unitSingletonBatchFiles, singletonBatchLaneCount, estimateUnitDurationMs)
+    : [];
 const unitFastExcludedFileSet = new Set(unitFastExcludedFiles);
 const unitFastCandidateFiles = allKnownUnitFiles.filter(
   (file) => !unitFastExcludedFileSet.has(file),
@@ -400,6 +431,11 @@ const unitHeavyEntries = heavyUnitBuckets.map((files, index) => ({
   name: `unit-heavy-${String(index + 1)}`,
   args: ["vitest", "run", "--config", "vitest.unit.config.ts", "--pool=forks", ...files],
 }));
+const unitSingletonEntries = unitSingletonBuckets.map((files, index) => ({
+  name:
+    unitSingletonBuckets.length === 1 ? "unit-singleton" : `unit-singleton-${String(index + 1)}`,
+  args: ["vitest", "run", "--config", "vitest.unit.config.ts", "--pool=forks", ...files],
+}));
 const baseRuns = [
   ...(shouldSplitUnitRuns
     ? [
@@ -420,7 +456,8 @@ const baseRuns = [
             ]
           : []),
         ...unitHeavyEntries,
-        ...unitAutoSingletonFiles.map((file) => ({
+        ...unitSingletonEntries,
+        ...unitMemorySingletonFiles.map((file) => ({
           name: `${path.basename(file, ".test.ts")}-isolated`,
           args: [
             "vitest",
@@ -756,6 +793,9 @@ const maxWorkersForRun = (name) => {
   if (resolvedOverride) {
     return resolvedOverride;
   }
+  if (name === "unit-singleton" || name.startsWith("unit-singleton-")) {
+    return 1;
+  }
   if (isCI && !isMacOS) {
     return null;
   }
diff --git a/scripts/test-runner-manifest.mjs b/scripts/test-runner-manifest.mjs
index 4e0ff9d0a5a..ee5644f3328 100644
--- a/scripts/test-runner-manifest.mjs
+++ b/scripts/test-runner-manifest.mjs
@@ -231,3 +231,18 @@ export function packFilesByDuration(files, bucketCount, estimateDurationMs) {
 
   return buckets.map((bucket) => bucket.files).filter((bucket) => bucket.length > 0);
 }
+
+export function dedupeFilesPreserveOrder(files, exclude = new Set()) {
+  const result = [];
+  const seen = new Set();
+
+  for (const file of files) {
+    if (exclude.has(file) || seen.has(file)) {
+      continue;
+    }
+    seen.add(file);
+    result.push(file);
+  }
+
+  return result;
+}
diff --git a/test/scripts/test-runner-manifest.test.ts b/test/scripts/test-runner-manifest.test.ts
index cd650ae2aad..0fac87c25e1 100644
--- a/test/scripts/test-runner-manifest.test.ts
+++ b/test/scripts/test-runner-manifest.test.ts
@@ -1,5 +1,7 @@
 import { describe, expect, it } from "vitest";
 import {
+  dedupeFilesPreserveOrder,
+  packFilesByDuration,
   selectMemoryHeavyFiles,
   selectTimedHeavyFiles,
   selectUnitHeavyFileGroups,
@@ -91,3 +93,44 @@ describe("scripts/test-runner-manifest memory selection", () => {
     });
   });
 });
+
+describe("dedupeFilesPreserveOrder", () => {
+  it("removes duplicates while keeping the first-seen order", () => {
+    expect(
+      dedupeFilesPreserveOrder([
+        "src/b.test.ts",
+        "src/a.test.ts",
+        "src/b.test.ts",
+        "src/c.test.ts",
+        "src/a.test.ts",
+      ]),
+    ).toEqual(["src/b.test.ts", "src/a.test.ts", "src/c.test.ts"]);
+  });
+
+  it("filters excluded files before deduping", () => {
+    expect(
+      dedupeFilesPreserveOrder(
+        ["src/a.test.ts", "src/b.test.ts", "src/c.test.ts", "src/b.test.ts"],
+        new Set(["src/b.test.ts"]),
+      ),
+    ).toEqual(["src/a.test.ts", "src/c.test.ts"]);
+  });
+});
+
+describe("packFilesByDuration", () => {
+  it("packs heavier files into the lightest remaining bucket", () => {
+    const durationByFile = {
+      "src/a.test.ts": 100,
+      "src/b.test.ts": 90,
+      "src/c.test.ts": 20,
+      "src/d.test.ts": 10,
+    } satisfies Record<string, number>;
+
+    expect(
+      packFilesByDuration(Object.keys(durationByFile), 2, (file) => durationByFile[file] ?? 0),
+    ).toEqual([
+      ["src/a.test.ts", "src/d.test.ts"],
+      ["src/b.test.ts", "src/c.test.ts"],
+    ]);
+  });
+});